Field of the Invention
The present invention relates to a composition for film formation, a resist underlayer film and a forming method thereof, a pattern-forming method, and a compound.
Discussion of the Background
In producing semiconductor devices and the like, a multilayer resist process has been utilized to increase the degree of integration of the semiconductor devices. In this process, in general, a composition for resist underlayer film formation is applied first on the upper face side of a substrate to provide a resist underlayer film. Next, a resist pattern is formed on the upper face side of this resist underlayer film. Subsequently, the resist pattern is transferred to the resist underlayer film through etching, and further, the resist underlayer film pattern is transferred to the substrate, whereby a desired pattern can be obtained. The resist underlayer film for use in such a multilayer resist process is required to have general characteristics such as optical characteristics, e.g. an appropriate refractive index and an appropriate extinction coefficient, and favorable etching resistance.
In recent years, in order to further increase the degree of integration, further microfabrication of a pattern has been in progress. In order to address this microfabrication, various investigations have been made on the structure of a compound contained in the composition for resist underlayer film formation, etc., and a functional group and the like which may be included in the compound, etc. (see Japanese Unexamined Patent Application, Publication No. 2004-177668).
Recently, in the multilayer resist process described above, a method involving forming a hard mask on the resist underlayer film by way of a CVD technique has been investigated. Specifically, in this process, an inorganic hard mask as an intermediate layer is made on the resist underlayer film by way of a CVD technique. In such a case where the inorganic hard mask is made by way of the CVD technique, in particular, when a nitride-based film is to be made, the substrate needs to be heated to a temperature of at least 300° C., and typically 400° C.
Moreover, recently, a pattern has been more frequently formed on/in a substrate having a plurality of kinds of trenches, in particular, trenches differing from one another in terms of an aspect ratio. Even in the case of such a substrate, the resist underlayer film is required to be formed such that these trenches are sufficiently filled with the resist underlayer film and the resist underlayer film exhibits superior flatness.